2031
ANGELONI ET AL CEREBRAL PERFUSION STRATEGIES IN AORTIC SURGERY
Stanford type A aortic dissection. J Thorac Cardiovasc Surg 2013;146:647–55. 10. Zierer A, Risteski P, El-Sayed Ahmad A, Moritz A, Diegeler A, Urbanski PP. The impact of unilateral versus bilateral antegrade cerebral perfusion on surgical outcomes after aortic arch replacement: a propensity-matched analysis. J Thorac Cardiovasc Surg 2014;147:1212–8. 11. Leshnower BG, Myung RJ, Chen EP. Aortic arch surgery using moderate hypothermia and unilateral selective antegrade cerebral perfusion. Ann Cardiothorac Surg 2013;2:288–95. 12. Stroup DF, Berlin JA, Morton SC, et al. Meta-analysis of observational studies in epidemiology: a proposal for
reporting. Meta-analysis of Observational Studies in Epidemiology (MOOSE) group. JAMA 2000;283:2008–12. 13. Merkkola P, Tulla H, Ronkainen A, et al. Incomplete circle of Willis and right axillary artery perfusion. Ann Thorac Surg 2006;82:74–80. 14. Urbanski PP, Lenos A, Blume JC, et al. Does anatomical completeness of the circle of Willis correlate with sufficient cross-perfusion during unilateral cerebral perfusion? Eur J Cardiothorac Surg 2008;33:402–8. 15. Kr€ ahenb€ uhl ES, Cl ement M, Reineke D, et al. Antegrade cerebral protection in thoracic aortic surgery: lessons from the past decade. Eur J Cardiothorac Surg 2010;38:46–51.
INVITED COMMENTARY Cerebral protection during aortic arch reconstruction remains a controversial topic, as there is no consensus regarding the optimal method to protect the brain during the period of hypothermic circulatory arrest (HCA). Current cerebral protection techniques use systemic hypothermia alone or in combination with adjunctive cerebral perfusion; however, strategies differ with regard to the degree of hypothermia and the method of cerebral perfusion (antegrade versus retrograde). In this issue of The Annals, Angeloni and colleagues [1] seek to determine the optimal method of delivering antegrade cerebral perfusion. The authors provide an update of their previous meta-analysis of data examining outcomes of arch reconstruction using unilateral (uASCP) or bilateral antegrade selective cerebral perfusion (bASCP) [2]. Using data from 32 publications, these authors compared outcomes between 3,065 patients receiving uASCP and 3,723 patients receiving bASCP during arch reconstruction. Their overall results demonstrated no significant difference between the two techniques in operative mortality, permanent neurologic dysfunction, or temporary neurologic dysfunction. However, in a metaregression analysis, HCA times longer than 30 minutes were associated with a significant increase in mortality only in patients receiving uASCP. This led to the authors’ major conclusion that “patients experiencing longer [circulatory arrest] times significantly benefit from bilateral ASCP.” The major problem with this conclusion is that the authors are correlating a method of cerebral protection during prolonged HCA with operative mortality. If the increase in the uASCP group mortality could be attributed solely to lethal neurologic outcomes, then the authors’ conclusions would be plausible. However, patients requiring prolonged HCA comprise a high-risk cohort of patients, and there are a multitude of other factors that could account for the increased mortality. It would be essential to know the percentage of aortic dissection and total arch replacements in the patients undergoing HCA
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
longer than 30 minutes, as well as their cause of death, to determine whether bASCP provided a significant advantage over uASCP. These data are not provided in the current manuscript. Therefore, the conclusions of Angeloni and colleagues are thought-provoking but remain in contradiction to both experimental and clinical propensity-matched data demonstrating no difference between uASCP or bASCP in cerebral perfusion efficacy, morbidity, or mortality in patients with mean HCA times longer than 40 minutes [3, 4]. Until a prospective randomized, controlled trial is conducted, this topic, like many others in cerebral protection, will continue to be debated. Bradley G. Leshnower, MD Surgery/Division of Cardiothoracic Surgery Emory University School of Medicine 1365-A Clifton Rd NE Ste 2236 Atlanta, GA 30306 e-mail: [email protected]
References 1. Angeloni E, Melina G, Refice SK, et al. Unilateral versus bilateral antegrade cerebral protection during aortic surgery: an updated meta-analysis. Ann Thorac Surg 2015;99:2024–31. 2. Angeloni E, Benedetto U, Takkenberg JJ, et al. Unilateral versus bilateral antegrade cerebral protection during circulatory arrest in aortic surgery: a meta-analysis of 5100 patients. J Thorac Cardiovasc Surg 2014;147:60–7. 3. Ye J, Dai G, Ryner LN, et al. Unilateral antegrade cerebral perfusion through the right axillary artery provides uniform flow distribution to both hemispheres of the brain: a magnetic resonance and histopathological study in pigs. Circulation 1999;100(19 Suppl):II309–15. 4. Zierer A, Risteski P, El-Sayed Ahmad A, Moritz A, Diegeler A, Urbanski PP. The impact of unilateral versus bilateral antegrade cerebral perfusion on surgical outcomes after aortic arch replacement: a propensity-matched analysis. J Thorac Cardiovasc Surg 2014:1471212–8.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.02.012
ADULT CARDIAC
Ann Thorac Surg 2015;99:2024–31
ANGELONI ET AL CEREBRAL PERFUSION STRATEGIES IN AORTIC SURGERY
Stanford type A aortic dissection. J Thorac Cardiovasc Surg 2013;146:647–55. 10. Zierer A, Risteski P, El-Sayed Ahmad A, Moritz A, Diegeler A, Urbanski PP. The impact of unilateral versus bilateral antegrade cerebral perfusion on surgical outcomes after aortic arch replacement: a propensity-matched analysis. J Thorac Cardiovasc Surg 2014;147:1212–8. 11. Leshnower BG, Myung RJ, Chen EP. Aortic arch surgery using moderate hypothermia and unilateral selective antegrade cerebral perfusion. Ann Cardiothorac Surg 2013;2:288–95. 12. Stroup DF, Berlin JA, Morton SC, et al. Meta-analysis of observational studies in epidemiology: a proposal for
reporting. Meta-analysis of Observational Studies in Epidemiology (MOOSE) group. JAMA 2000;283:2008–12. 13. Merkkola P, Tulla H, Ronkainen A, et al. Incomplete circle of Willis and right axillary artery perfusion. Ann Thorac Surg 2006;82:74–80. 14. Urbanski PP, Lenos A, Blume JC, et al. Does anatomical completeness of the circle of Willis correlate with sufficient cross-perfusion during unilateral cerebral perfusion? Eur J Cardiothorac Surg 2008;33:402–8. 15. Kr€ ahenb€ uhl ES, Cl ement M, Reineke D, et al. Antegrade cerebral protection in thoracic aortic surgery: lessons from the past decade. Eur J Cardiothorac Surg 2010;38:46–51.
INVITED COMMENTARY Cerebral protection during aortic arch reconstruction remains a controversial topic, as there is no consensus regarding the optimal method to protect the brain during the period of hypothermic circulatory arrest (HCA). Current cerebral protection techniques use systemic hypothermia alone or in combination with adjunctive cerebral perfusion; however, strategies differ with regard to the degree of hypothermia and the method of cerebral perfusion (antegrade versus retrograde). In this issue of The Annals, Angeloni and colleagues [1] seek to determine the optimal method of delivering antegrade cerebral perfusion. The authors provide an update of their previous meta-analysis of data examining outcomes of arch reconstruction using unilateral (uASCP) or bilateral antegrade selective cerebral perfusion (bASCP) [2]. Using data from 32 publications, these authors compared outcomes between 3,065 patients receiving uASCP and 3,723 patients receiving bASCP during arch reconstruction. Their overall results demonstrated no significant difference between the two techniques in operative mortality, permanent neurologic dysfunction, or temporary neurologic dysfunction. However, in a metaregression analysis, HCA times longer than 30 minutes were associated with a significant increase in mortality only in patients receiving uASCP. This led to the authors’ major conclusion that “patients experiencing longer [circulatory arrest] times significantly benefit from bilateral ASCP.” The major problem with this conclusion is that the authors are correlating a method of cerebral protection during prolonged HCA with operative mortality. If the increase in the uASCP group mortality could be attributed solely to lethal neurologic outcomes, then the authors’ conclusions would be plausible. However, patients requiring prolonged HCA comprise a high-risk cohort of patients, and there are a multitude of other factors that could account for the increased mortality. It would be essential to know the percentage of aortic dissection and total arch replacements in the patients undergoing HCA
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
longer than 30 minutes, as well as their cause of death, to determine whether bASCP provided a significant advantage over uASCP. These data are not provided in the current manuscript. Therefore, the conclusions of Angeloni and colleagues are thought-provoking but remain in contradiction to both experimental and clinical propensity-matched data demonstrating no difference between uASCP or bASCP in cerebral perfusion efficacy, morbidity, or mortality in patients with mean HCA times longer than 40 minutes [3, 4]. Until a prospective randomized, controlled trial is conducted, this topic, like many others in cerebral protection, will continue to be debated. Bradley G. Leshnower, MD Surgery/Division of Cardiothoracic Surgery Emory University School of Medicine 1365-A Clifton Rd NE Ste 2236 Atlanta, GA 30306 e-mail: [email protected]
References 1. Angeloni E, Melina G, Refice SK, et al. Unilateral versus bilateral antegrade cerebral protection during aortic surgery: an updated meta-analysis. Ann Thorac Surg 2015;99:2024–31. 2. Angeloni E, Benedetto U, Takkenberg JJ, et al. Unilateral versus bilateral antegrade cerebral protection during circulatory arrest in aortic surgery: a meta-analysis of 5100 patients. J Thorac Cardiovasc Surg 2014;147:60–7. 3. Ye J, Dai G, Ryner LN, et al. Unilateral antegrade cerebral perfusion through the right axillary artery provides uniform flow distribution to both hemispheres of the brain: a magnetic resonance and histopathological study in pigs. Circulation 1999;100(19 Suppl):II309–15. 4. Zierer A, Risteski P, El-Sayed Ahmad A, Moritz A, Diegeler A, Urbanski PP. The impact of unilateral versus bilateral antegrade cerebral perfusion on surgical outcomes after aortic arch replacement: a propensity-matched analysis. J Thorac Cardiovasc Surg 2014:1471212–8.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.02.012
ADULT CARDIAC
Ann Thorac Surg 2015;99:2024–31
